Saturday, April 28, 2012

Please recheck those Great Egrets

Great Egrets Ardea alba (Casmerodius alba) is a very common bird of Sabah. It can be found in coastal lagoons, beaches, shores, paddy fields and river banks. It is also the largest egret in Sabah, both as a winter visitor and also a local breeding resident, see photo here. A brief write up of its breeding in Sabah will be appearing in Suara Enggang, being the first photodocumented breeding of this species here.

It is easy to distinguish this species from the other white egrets occurring here, so its features will not be elaborated. It is so common here that there seems to be nothing more to write on them,  however, the following image taken by me in Tawau in November 2011 changed that.

Great Egret ranges from 85-102 cm (Robson), 80-104 cm (Brazil and Myer) which means that the largest bird is 24cm (about 10 inches) larger than the smallest one.

There are four essentially allopatric subspecies: alba (southern Palearctic from central Europe to Russian Far East), modesta (India to northeastern China and Japan to Australia), melanorhyncha (sub-Saharan Africa and Madagascar), and egretta (North and South America). At present, some authors split the old world Great Egret into Eastern (A. a. modesta) and Western (A. a. alba) Great Egrets. The split is still strongly disputed by many and is not widely accepted pending further and more convincing research. For the purpose of my little piece here, we will treat them as subspecies and not distinct species.

Historically all birds in Borneo are of modesta race, there has not been any record of alba race in Borneo and in Malaysia. However, when Chris Kehoe saw this image, he alerted me that there could be a bird of the alba race due to its larger size and paler legs. As the two races are extremely similar, we could not be absolutely certain without looking at further photographic evidence.   I have deleted all the other photos taken on that day leaving this one as it shows the range in size of the two egrets nicely. I could not remember having any impression of a larger bird while photographing them, so this could very well be a normal sized bird with a smaller one. But than again I have deleted all my other photos, so nothing further can be done from here.

I write this piece here to alert birders in Borneo to pay attention to any peculiar looking Great Egret they come across, it could be the alba race, which has not yet been recorded here.
According to Brazil in Birds of East Asia, the alba race;
a. is larger than modesta,
b. has pale or bright yellow tarsi and toes in winter plumage, and
c. has been noted to winter further and further south of their usual range (C. Honshu to Kyushu and Korea), so it might accidentally land on the west coast of Sabah, just like the Red-billed Starling did in December 2011.

While size difference is a distinguishing factor, bear in mind that size in images can be deceiving as seen in the following two images, which are of the same birds but appearing vastly different in size in each image.

Happy birding.

Wednesday, April 4, 2012

Rare bird sightings in Sabah - 1st Quarter 2012

The list shows the notable bird sightings in Sabah in the first quarter of 2012, it was quite uneventful when compared to the last quarter of 2011, where a number of super rare birds were recorded.
There was no notable bird sighting in March 2012.

Edited to add:  Many thanks to Master Sifu Ck Leong who wrote in to update "Common Kestrel female at Brunei river by CK Leong and Roger Rajah on March 05, 2012". 

Edited to add on 5th April 2012: As I do not know how to upload a Word file here.A Word file with clickable link to the relevant images is at Borneo Bird Images Document list.

Happy birding.

Photodocument of Wild Birds of Borneo.

Standard References for my blog.

Tuesday, April 3, 2012

Dusky/Dark morph Eurasian Tree Sparrow.

Eurasian Tree Sparrow Passer montanus,  is a very common bird in Borneo, co-existing happily with human. 

They feed on excess rice and bread crumbs thrown out of the kitchen, and often seen bathing in puddles at road side after a shower. The urban ones even feed inside food stalls and coffee shops.

While common as they are, individuals with plumage variations are hard to chance upon. 

Here, I share some photos I took of a dark morph individual, it was playing with other normal looking birds in a puddle after a shower, the rising heat wave had created havoc to the image. The images were taken in Tinagat, Tawau. You could see the obvious differences in plumage with the normal looking individuals.

Here it flew to land on an overhead cable. The belly is darkish grey and the upperparts patterns are indistinct.

Here is a image of a normal looking adult feeding a juvenile for comparison.

Here is another picture taken in Sahabat, Lahad Datu by Victor Luke Petrus, showing two dark morph individuals.
Image courtesy of Victor Luke Petrus

There could be more of them around, and next time you see some common Eurasian Tree Sparrow, do not write them off right away.

Happy birding.

Photodocument of Wild Birds of Borneo.

Standard References for my blog.